Calibration block



FIG. 1 is a front perspective view of a calibration block, showing our new design;

FIG. 2 is a back perspective view thereof;

FIG. 3 is a front elevation view thereof;

FIG. 4 is a rear elevation view thereof;

FIG. 5 is a top plan view thereof;

FIG. 6 is a bottom plan view thereof;

FIG. 7 is a left side elevation view thereof;

FIG. 8 is a right side elevation view thereof; and,

FIG. 9 is a second front perspective view thereof, shown with environment.

The broken lines are directed to environment and form no part of the claimed design.

The wire frame lines shown throughout the views are intended to indicate surface contour. 

CLAIM We claim the ornamental design for a calibration block, as shown and described. 